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Towards unexplored intermolecular n→π* interactions, presented herein are the synthesis, structure, self‐assembly and function of a multicarbonyl‐containing macrocycle calix[2]arene[2]barbiturate 1. X‐ray single crystal diffraction reveals the presence of Cl⋅⋅⋅C=O interactions in CH2Cl2⊂1 host‐guest complex and multiple intermolecular C=O⋅⋅⋅C=O interactions between molecules 1 in crystalline state. The intermolecular C=O⋅⋅⋅C=O interactions as attractive driving force led to unprecedented self‐assembly of nanotube with diameter around 1.4 nm and inner surface engineered by aromatic rings. SEM and TEM images of the self‐assembly of 1 demonstrated temperature‐dependent morphologies which allows the observation of spheres at 25 °C and rods at 0 °C, respectively. XRD analysis indicated consistent hexagonal patterns in the self‐assembly and single crystal lattice, indicating the nanotubes driven by C=O⋅⋅⋅C=O interactions constitute the basic structural architectures of both aggregates. The nanoscopic tubes (pores) formed in the rodlike single crystal engendering the separation of moving dyes were preliminarily investigated by a single‐crystal chromatography and crystal‐packed column chromatography. [ABSTRACT FROM AUTHOR]

A new kind of nucleating agent for poly( l -lactic acid) (PLLA), N,N'-bis(benzoyl) hexanedioic acid dihydrazide (BHAD), was synthesized. Differential scanning calorimetry (DSC), polarization optical microscopy (POM), wide-angle X-ray diffraction (WAXD) and rheometer were used to study the crystallization behavior and crystal morphology of PLLA nucleated by BHAD. In order to ensure the same thermal history of the samples characterized by DSC, POM and XRD, these samples were all thermally treated by DSC. In nonisothermal crystallization, BHAD showed excellent nucleating ability to PLLA. However, it was different from the traditional heterogeneous nucleation mechanism. POM observation showed that morphologies of PLLA crystals varied with the concentration of BHAD and can be classified into three types. Through the systematic investigation of DSC, POM and rheological analysis, it was clearly demonstrated that BHAD had solubility in PLLA matrix, depending on its concentration and processing temperature. Consequently, a highly schematic binary phase diagram of the PLLA/BHAD system was presented, accompanied with a reasonable mechanism of how the PLLA crystal morphologies controlled by BHAD. [ABSTRACT FROM AUTHOR]

Nearly monodisperse CdS hierarchical hollow nanospheres have been synthesized on a large scale through a Na3cit-assisted solution route. The hollow structure has an application as a drug carrier and the CdS building blocks have fluorescent capabilities. The T1-agent, Gd–DTPA, is then conjugated to the CdS hierarchical hollow nanospheres through N-ethyl-N′-[3-(dimethylamino)propyl]carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling chemistry using surface absorbed Na3cit molecules as an intermedium. Thus, multifunctional magnetic-fluorescent CdS@Gd–DTPA hierarchical hollow nanospheres are formed, which combine magnetic resonance imaging (MRI), fluorescent imaging and drug delivery into one system. The as-prepared products are characterized in detail by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Fourier transform infrared spectrometry. The room temperature photoluminescent spectra and T1-weighted maps of the obtained CdS@Gd–DTPA are carried out using a fluorescence spectrophotometer and a 3 T MRI scanner, respectively. The results indicate that the as-prepared product is a potential candidate for simultaneous disease diagnosis and therapy by combining the multiplexing imaging capability. [ABSTRACT FROM AUTHOR]

Abstract: LiNbO3 (LNO) films were epitaxially grown on n-type GaN templates using pulsed laser deposition technique. The microstructures and electrical properties of the LNO/GaN heterostructure were characterized by x-ray diffraction, transmission electron microscope, and capacitance–voltage (C–V) measurements. The LNO films had two variants of grains rotated 60° in-plane to each other. The epitaxial relationship of the respective variants could be built as [10–10]LNO//[1–210]GaN and [1–100]LNO//[11–20]GaN via 30° in-plane rotation of the LNO film relative to the GaN layer. Interface analysis of the heterostructure demonstrated that two different epitaxial growth mechanisms vertical heteroepitaxy and lateral homoepitaxy, should happen at the interface of LNO/GaN. Counterclockwise C–V windows induced by the ferroelectric polarizations of LNO film could be observed clearly. The size of the window increased with increasing the sweep bias and a large window of 5.8V was achieved at ±15V. By solving Poisson and drift–diffusion equations, the physical mechanisms of the C–V characteristics were demonstrated. [Copyright &y& Elsevier]

Abstract: Platinum nanoparticles (Pt-NPs) were deposited onto N-(trimethoxy-silylpropyl) ethylenediamine triacetic acid (EDTA-silane) modified reduced graphene oxide (EDTA-RGO). The EDTA-RGO/Pt-NPs were coated onto a glass carbon electrode and characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, and electrochemical tests. The chelating groups create a micro-environment that is suitable for the catalytic behavior of Pt-NPs. Compared with traditional carbon-based Pt catalysts, EDTA-RGO/Pt-NPs exhibit great tolerance towards poisoning by CO. Graphene-supported Pt nanoparticles can be used for the fabrication of fuel cell electrodes and other catalytic devices. [Copyright &y& Elsevier]

Bilayer multiferroic thin films of Pb(Zr0.52Ti0.48)O3/Ni0.8Zn0.2Fe2O4 (PZT/NZF) were prepared on SrTiO3(001) substrate via pulsed laser deposition. X-ray diffraction results showed the highly epitaxial (001)-orientation of the bilayer thin films were successfully fabricated. The remnant polarization 2Pr and coercive field Ec are 98.3μC/cm2 and 370kV/cm in the bilayer thin films, 46.1μC/cm2 and 115kV/cm in the pure PZT film. The polarization and electric breakdown voltage were enhanced by about one time, which may be attributed to the tensile stress of the NZF layer onto the PZT layer, resulting in the elongated c-axis of the PZT. In addition, the saturation magnetization and coercive field for the bilayer films are 256.2emu/cm3 and 273.6Oe in-plane, respectively. As a comparison, the corresponded values for the pure NZF film are 270.8emu/cm3 and 367.3Oe in-plane, which revealed that the ferromagnetic properties of the bilayer films have been decreased, which may be due to the compressive stress of the PZT layer under the NZF layer. Our results indicate that the existing interfacial strain in PZT/NFO bilayer films can result in the improvement of the ferroelectric properties and the reduction of the ferromagnetic properties. [ABSTRACT FROM AUTHOR]

Abstract: A new series of 1,5-disubstituted 1,3,5-hexahydrotriazine-2-N-nitroimines (4a–4x) were designed and synthesized as novel chiral neonicotinoid analogues. The single-crystal structure of 4n was further determined by X-ray diffraction, and its S configuration was confirmed. Preliminary bioassay showed that compound 4e, 4k, 4u, 4v exhibited excellent insecticidal activities at 100 mg/L, while 4k had >90% mortality at 10 mg/L, which suggested it could be used as a lead for future development. Modeling the inhibitor-nAChR complexes by molecular docking studies explained the structure–activity relationships observed in vitro, and revealed an intriguing molecular binding mode at the active site of nAChR, which raised the possibility that these analogues may arbitrate their insecticidal activity through a mechanism other than imidacloprid. [Copyright &y& Elsevier]

SrTiO3 (STO) dielectric film with TiO2 buffer was grown on AlGaN/GaN heterostructures by pulsed laser deposition (PLD). X-ray diffraction (XRD) characterization showed that highly (111)-oriented STO film was fabricated at 500°C with the TiO2 buffer. Electrical properties of MOS-HFET with 100 nm STO and 10 nm TiO2 buffer were investigated. The current-voltage (I-V) curves displayed a lower of 4.6×10-10 A at a gate voltage of -4 V, comparing with HFETs without STO/TiO2 dielectric layer. From the capacitance-voltage (C-V) curves, the total interfacial states density was estimated to be less than 1012 cm-2eV-1.The dielectric constant was determined to be 110, and Equivalent Oxide Thickness (EOT) was about 3.6 nm. It was found that the introduction of buffer led to the following effects: (1) inducing the crystal of STO at a low temperature, (2) decreasing the interfacial states density, (3) achieving small gate leakage current density. Thus, the integrated MOS-HFET can show good electrical characteristics for further possible applications. [ABSTRACT FROM AUTHOR]

(111) oriented PbZr0.52Ti0.48O3 thin films were epitaxially grown on SrRuO3 and SrRuO3/Pt electrode coated Al2O3(0001) substrates by pulsed-laser deposition, respectively. The X-ray diffraction analysis revealed that PZT films on SrRuO3/Pt electrode had better crystal quality than the films on SrRuO3 electrode. Compared to the SrRuO3 electrode, the SrRuO3/Pt hybrid electrode could significantly improve ferroelectric properties of PbZr0.52Ti0.48O3 films with 1 times larger remnant polarization (2Pr = 40.1 μC/cm2), 0.4 times smaller coercive field (2Ec = 40 kV/cm), better fatigue endurance (8.8% degradation at 1011 switching cycles) and lower leakage current density (10-8 A/cm2 at an applied voltage of 5 V). The reliable ferroelectric properties in PbZr0.52Ti0.48O3 films with SrRuO3/Pt hybrid electrode indicate that the combination of the excellent fatigue behavior using SrRuO3 electrodes with the low leakage currents with Pt electrodes can be suitable for the application of integrated ferroelectric devices. [ABSTRACT FROM AUTHOR]

Abstract: Cubic-like CeO2 nanocrystals were successfully synthesized through an improved-toluene solvothermal process using hexadecylamine (HAD) as a capping agent and CeCl3·7H2O as a precursor at 180°C for 24h. These nanocubes are about 10nm in size, and have a tendency to assemble into 2D superstructure. The obtained samples were characterized by means of X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). It was found that the water content, the concentration of ligand and kinds of aliphatic amine played important roles in the formation of the novel morphology. A possible formation mechanism was proposed based on the controlling reaction parameters. The electrochemical and photocatalytic properties of the as-synthesized samples exhibited the size/shape-dependent properties and potential applications. [Copyright &y& Elsevier]

CuInS 2 thin films incorporating with cerium have been successfully fabricated by a powder metallurgy method. X-ray diffraction and scanning electron microscope measurements showed that the as-prepared CuIn 1− x Ce x S 2 samples crystallize with chalcopyrite structure at 250 °C and the crystallinity and film compactness could be improved as annealing temperature rises. In the ultraviolet–visible–near infrared spectrum, two additional light absorption peaks were observed at 1690 nm and 1930 nm. The optical bandgaps of CuIn 1− x Ce x S 2 films decrease from 1.38 eV to 1.34 eV with increasing cerium content. These observed optical behaviors could suggest that an intermediate band forms in the forbidden band of CuInS 2 semiconductor due to cerium incorporation. The position of intermediate band locates at 0.64 eV below conduction-band bottom. This kind of rare-earth doped materials enhances long-wavelength absorption, which could be helpful for high-efficiency solar cells. [ABSTRACT FROM AUTHOR]

Abstract: Ultra-long and flexible necklace-like nanostructures of cadmium hydroxide were successfully prepared in the n-octanol/aqueous liquid system through the microwave heating approach, and a novel mechanism based on the synergistic effect of bubble-template and interface-assistance (SEBI) was proposed. The obtained products were carefully characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), FT-IR spectrum, UV–vis adsorption spectrum and BET measurement. Control experiments revealed that the morphologies of the building blocks and the final products could be readily tuned by the reaction parameters. Further experiments evidenced that the positively charged Cd(OH)2 could effectively adsorb or separate the negatively charged dye molecules, and the hierarchical structure could improve its separation performance. [Copyright &y& Elsevier]

Abstract: Ferroelectric and dielectric properties of tungsten-doped Bi4Ti3O12-SrBi4Ti4O15 ceramics were investigated. A pure phase of all the samples is confirmed by X-ray diffraction patterns. The remanent polarization (2P r) of the samples increases initially and reaches its maximum value of 43.2μC/cm2 when W content is 0.03, which is over twice as large as that of non-doped one, then decreases with further doping. The coercive field (E c) shows a weak tungsten content dependency. It is considered that the enlarged 2P r could be mainly attributed to the restraint of oxygen vacancies as well as the weakening of their mobility. The Curie temperature decreases a little with increasing doping content, which indicates the good thermal stability is not deteriorated by tungsten doping. [Copyright &y& Elsevier]

Synthesis of Er3+, Eu3+ ions activated strontium hexa-aluminate phosphor using the combustion method is described. An efficient phosphor can be prepared by this method at reaction temperatures as low as 500°C in a few minutes. Powder X-ray diffraction and the optical properties were studied by photoluminescence spectra. [ABSTRACT FROM AUTHOR]

Abstract: A series of metallic LaNiO3 (LNO) thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD) under the oxygen pressure of 20Pa at different substrate temperatures from 450 to 750°C. X-ray diffraction (XRD) was used to characterize the crystal structure of LNO films. θ–2θ scans of XRD indicate that LNO film deposited at a substrate temperature of 700°C has a high orientation of (l l 0). At other substrate temperatures, the LNO films have mixed phases of (l l 0) and (l 00). Furthermore, pole figure measurements show that LNO thin films, with the bicrystalline structure, were epitaxially deposited on MgO (100) substrates in the mode of LNO (110)//MgO (100) at 700°C. Reflection high-energy electric diffraction (RHEED) and atomic force microscopy (AFM) were also performed to investigate the microstructure of LNO films with the high (l l 0) orientation. RHEED patterns clearly confirm this epitaxial relationship. An atomically smooth surface of LNO films at 700°C was obtained. In addition, bicrystalline epitaxial LNO films, fabricated at 700°C, present a excellent conductivity with a lower electrical resistivity of 300μΩcm. Thus, the obtained results indicate that bicystalline epitaxial LNO films could serve as a promising candidate of electrode materials for the fabrication of ferroelectric or dielectric films. [Copyright &y& Elsevier]

Cubes of CuBr with an average dimensions of 0.3–0.8 μm have been prepared by a simple reaction between CuO suspension, NH2OH and KBr in the presence of deionized gelatin at 40°C. Gelatin played a decisive role as an inhibitor of the direct attack of NH2OH, KBr to CuO surfaces and coagulation of the growing CuBr in producing the cubes. The products were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectra techniques and UV-visible absorption spectroscopy. The sizes of the subunits of the polycrystalline CuBr particles were estimated by Debye–Scherrer formula according to XRD spectrum. [Copyright &y& Elsevier]

Au and Ag Noble metals nanowire arrays have been successfully prepared by a photochemical method in porous anodic aluminum oxide template from an aqueous solution of HAuCl4 and AgNO3 in the presence of polymer capping materials PVA at room temperature. The products were characterized by XRD, TEM and SEM. These nanowires have uniform diameters of about 20 nm, which correspond to the pore sizes of the templates used, and lengths are up to tens of micrometers. This approach can be used to fabricate crystalline nanowire arrays of a wide range of other metals and semiconductor materials. [Copyright &y& Elsevier]

Orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 nanofibers were prepared by electrospinning followed by a heat treatment. The effects of post-annealing temperatures on the phase composition, microstructure and morphology were investigated by XRD, SEM, HRTEM and XPS. Negative thermal expansion (NTE) behaviors of the In 0.5 Sc 1.5 Mo 3 O 12 nanofibers were analyzed by high-temperature XRD. Results indicate that the as-prepared In 0.5 Sc 1.5 Mo 3 O 12 nanofibers show an amorphous structure with smooth and homogeneous shape. The average diameter of the as-prepared In 0.5 Sc 1.5 Mo 3 O 12 nanofibers is around 515 nm. Well crystallized orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 nanofibers could be prepared after post-annealing at 550 °C for 2 h with an average diameter of about 192 nm. The crystallinity of In 0.5 Sc 1.5 Mo 3 O 12 nanofibers gradually improved with the increase of annealing temperature. However, too high post-annealing temperature leads to a damage of sample's fiber structure. The high-temperature XRD results reveal that In 0.5 Sc 1.5 Mo 3 O 12 nanofibers show an anisotropic NTE, and the coefficients of thermal expansion (CTEs) along a -axis and c -axis were −5.95 × 10−6 °C−1 and -3.54 × 10−6 °C−1, while the one along b -axis is 5.61 × 10−6 °C−1. The volumetric CTE of In 0.5 Sc 1.5 Mo 3 O 12 nanofibers is −3.90 × 10−6 °C−1 and the linear one is 1.3 × 10−6 °C−1 in 25–700 °C. [ABSTRACT FROM AUTHOR]

The diastereomers 10-N-[2-fluoro-6-chloro-9H-9-purinyl]-(9R, 10R)-dihydroartemisinin(A) and10-N-[2-fluoro-6-chloro-9H-9-purinyl]-(9S, 10S)-dihydroartemisinin(B) were obtained via a trifluoroacetic acid catalyzed procedure simultaneously. Their structures were characterized by HRMS, MS, 1H-NMR, 13C-NMR, 2D NMR(COSY) and IR spectroscopy, and the configurations were further confirmed by X-Ray diffraction and Density functional theory (DFT). Then, the intermolecular interactions were studied mainly through Hershfield surface (HS), molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) methods. Finally, preliminary anticancer evaluations of A and B were conducted in human breast tumor cell lines (MDA-MB-436, T47D) and a normal mammary epithelial cell line (MCF-10A). The GI50 of A and B were better or comparable to the positive drug mercaptopurine (6-MP), and both of novel compounds did not display significant cytotoxicity toward MCF-10A. [ABSTRACT FROM AUTHOR]

White phosphorus (P4) undergoes degradation to P2 moieties if exposed to the new N,N‐bis(silylenyl)aniline PhNSi21 (Si=Si[N(tBu)]2CPh), furnishing the first isolable 2,5‐disila‐3,4‐diphosphapyrrole 2 and the two novel functionalized Si=P doubly bonded compounds 3 and 4. The pathways for the transformation of the non‐aromatic 2,5‐disila‐3,4‐diphosphapyrrole PhNSi2P22 into 3 and 4 could be uncovered. It became evident that 2 reacts readily with both reactants P4 and 1 to afford either the polycyclic Si=P‐containing product [PhNSi2P2]2P23 or the unprecedented conjugated Si=P−Si=P−Si=NPh chain‐containing compound 4, depending on the employed molar ratio of 1 and P4 as well as the reaction conditions. Compounds 3 and 4 can be converted into each other by reactions with 1 and P4, respectively. All new compounds 1–4 were unequivocally characterized including by single‐crystal X‐ray diffraction analysis. In addition, the electronic structures of 2–4 were established by Density Functional Theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

White phosphorus (P4) undergoes degradation to P2 moieties if exposed to the new N,N‐bis(silylenyl)aniline PhNSi21 (Si=Si[N(tBu)]2CPh), furnishing the first isolable 2,5‐disila‐3,4‐diphosphapyrrole 2 and the two novel functionalized Si=P doubly bonded compounds 3 and 4. The pathways for the transformation of the non‐aromatic 2,5‐disila‐3,4‐diphosphapyrrole PhNSi2P22 into 3 and 4 could be uncovered. It became evident that 2 reacts readily with both reactants P4 and 1 to afford either the polycyclic Si=P‐containing product [PhNSi2P2]2P23 or the unprecedented conjugated Si=P−Si=P−Si=NPh chain‐containing compound 4, depending on the employed molar ratio of 1 and P4 as well as the reaction conditions. Compounds 3 and 4 can be converted into each other by reactions with 1 and P4, respectively. All new compounds 1–4 were unequivocally characterized including by single‐crystal X‐ray diffraction analysis. In addition, the electronic structures of 2–4 were established by Density Functional Theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Heteroepitaxial GaN films are grown on sapphire (0001) substrates using laser molecular beam epitaxy. The growth processes are in-situ monitored by reflection high energy electron diffraction. It is revealed that the growth mode of GaN transformed from three-dimensional (3D) island mode to two-dimensional (2D) layer-by-layer mode with the increase of thickness. This paper investigates the interfacial strain relaxation of GaN films by analysing their diffraction patterns. Calculation shows that the strain is completely relaxed when the thickness reaches 15 nm. The surface morphology evolution indicates that island merging and reduction of the island-edge barrier provide an effective way to make GaN films follow a 2D layer-by-layer growth mode. The 110-nm GaN films with a 2D growth mode have smooth regular hexagonal shapes. The X-ray diffraction indicates that thickness has a significant effect on the crystallized quality of GaN thin films. [ABSTRACT FROM AUTHOR]

Typical perovskite oxides SrTiO3 (STO) and PbZr0.52Ti0.48O3 (PZT) were fabricated on GaN semiconductor substrates by pulsed laser deposition. STO and PZT films were deposited on bare GaN, TiO2, and MgO-buffered GaN. The effects of TiO2 and MgO buffer-layers on the orientations and electric properties of the perovskite films were systematically studied. The crystalline properties were in situ monitored by reflective high energy electron diffraction and ex situ characterized by X-ray diffraction. It was found that the epitaxial temperature of STO and PZT was reduced by inserting a buffer layer. (111)-oriented films were obtained on bare and TiO2-buffered GaN. However, the orientations of the perovskite films were changed to be (110) when deposited on MgO buffer layer. Furthermore, PZT films deposited on MgO- and TiO2-buffered GaN show better electric performance compared with these films directly deposited on GaN. These results show that perovskite oxide could be epitaxially grown on GaN semiconductor substrates by inserting a proper buffer layer. [ABSTRACT FROM PUBLISHER]

A series of novel symmetrical trans-bis-Schiff bases ( 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h, 11i, 11j, 11k, 11l, 11m) were designed and prepared as novel anticancer analogues, with the trans-configuration confirmed by X-ray diffraction. Preliminary inhibitory effects of these compounds on CML K562 cell growth were investigated, and the potential analogue 11e showed an excellent anti-leukemia activity (IC50=6.35 μg/mL), which is higher than that of the clinical drug 5-fluorouracil (IC50=8.48 μg/mL). Complete assignments had been achieved for the title compounds by spectroscopic techniques, and their have been studied. [ABSTRACT FROM AUTHOR]

Abstract: A novel series of bis-aromatic ring neonicotinoid analogues (1a–1l, 2a–2c), were designed and prepared by introducing a new substituted aromatic ring into nitenpyram and forming a tetrahydropyrimidine ring, with the cis-configuration confirmed by X-ray diffraction. Preliminary bioassays showed most analogues exhibited good insecticidal activities at 100mg/L, and compound 1d and 2a were highly potent even at 10mg/L. Modeling the ligand–receptor complexes by molecular docking study explained the structure–activity relationships observed in vitro, which may provide some useful information for future design of new insecticides. [Copyright &y& Elsevier]

Abstract: The concentric precipitate rings are found in urinary stone section and may relate to Liesegang pattern and formation mechanism of urinary stone. Urinary stone is mainly composed of calcium oxalate, so it is significant to study the concentric precipitate rings. The influence of RE3+ on the formation of calcium oxalate concentric precipitate rings is studied for the first time in two-dimensional agar gel systems. Precipitate rings are characterized by means of Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and biomicroscope with digital camera. The results show concentric precipitate rings are made of calcium oxalate and RE3+ promote the present of rings. The number of concentric rings are influenced by different RE3+ and the reaction time. The agar gel systems are helpful for the ions to diffuse uniformly, and as a medium where calcium oxalate rings are formed. In comparison with Gd3+ and La3+ ions, the content and size of calcium oxalate monohydrate (COM) crystals are highest and biggest after the addition of Er3+ ions, indicating that Er3+ ions promote the formation of concentric rings effectively. However, in the similar systems containing Cu2+, Fe2+, Fe3+and Co2+, we found the ring only appeared in the system containing Fe3+ ions. And the formation mechanism of the calcium oxalate concentric precipitate rings in two-dimensional agar gel systems containing rare earth ions is also discussed in the paper. [Copyright &y& Elsevier]

Abstract: The present paper describes the synthesis of europium-doped calcium aluminate phosphor using the combustion method. An efficient blue emission phosphor can be prepared at reaction temperatures as low as 500°C in a few minutes by this method. Characterization of the powder was done by X-ray diffraction, transmission electron microscopy, scanning electron microscope analysis and the optical properties were studied by photoluminescence spectra. Thermoluminescence (TL) studies also have been carried out on CaAl12O19:Eu2+ phosphor. The TL glow curve shows peaks at 174 and 240°C. Defect centres formed in irradiated phosphor have been studied using the technique of electron spin resonance. Step annealing measurements indicate that one of the annealing stages of a defect centre appear to correlate with the release of carriers resulting in TL peak at 174°C. The centre is characterized by an isotropic g-value of 2.0046 and is assigned to a F+ centre. [Copyright &y& Elsevier]

A novel synthetic route for the preparation of CdS nanowires has been developed. CdS nanowires with a diameter of ca. 4 nm have been successfully prepared by the microwave irradiation of a complex of cadmium-1-pyrrlidine dithio carboxylic acid ammonium (C5H12N2S2, APDTC) [Cd(APDTC)2]2 in an ethylenediamine solution. The CdS nanowires were characterized by powder X-ray diffraction pattern, transmission electron microscopy (TEM), UV-Vis spectroscopy, diffuse reflection spectroscopy and PL spectroscopy. [Copyright &y& Elsevier]

Bowl inversion is a unique property of buckybowls. The polarity and assembly configuration of buckybowls are reversed after bowl inversion. So far, this unique phenomenon has been studied in solution and on surface, but not in solid state due to spatial constraint. Now a series of exo‐type supramolecular assemblies of trithiasumanene and nanographene are investigated. Tuning the electron density of the nanogaphene component was found to directly affect the binding constant of the complex. Reversible bowl inversion in the solid state was then successfully achieved by subjecting the trithiasumanene–nanographene assembly with the weakest binding strength to repeated heating–cooling cycles, which was unambiguously observed by single crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

Bowl inversion is a unique property of buckybowls. The polarity and assembly configuration of buckybowls are reversed after bowl inversion. So far, this unique phenomenon has been studied in solution and on surface, but not in solid state due to spatial constraint. Now a series of exo‐type supramolecular assemblies of trithiasumanene and nanographene are investigated. Tuning the electron density of the nanogaphene component was found to directly affect the binding constant of the complex. Reversible bowl inversion in the solid state was then successfully achieved by subjecting the trithiasumanene–nanographene assembly with the weakest binding strength to repeated heating–cooling cycles, which was unambiguously observed by single crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

We report a special example of chemiluminescent dearomatisation reaction between metalated pyrrole and 1O 2. The mechanism of photooxygenation of complex 1 is proposed via a stepwise [2+2]-cycloaddition of 1O 2 following by ring-opening to generate a ketoamide complex 2. [Display omitted] Visible-light-mediated dearomatisation of pyrroles is a powerful strategy for the synthesis of pharmaceuticals and bioactive compounds. Herein we present the chemiluminescent reaction between pyrrole metalated-Ir(III) complex [Ir(K 2 C, N -DPP)(H)(Cl)(PPh 3) 2 ] (1) and singlet oxygen to form a ketoamide complex [Ir(K2 C, N -ketoamide)(H)(Cl)(PPh 3) 2 ] (2). Complex 2 are fully characterized by NMR and single crystal X-ray diffraction analysis. The reaction mechanism of metalated pyrrole-singlet reaction upon irradiation is studied by experiment and DFT calculations. [ABSTRACT FROM AUTHOR]

A novel, two-chamber electrolysis cell equipped with an ion exchange membrane and a magnesium anode was proposed in this study to recover phosphate as struvite from both the simulated and real biogas digestion slurry of swine wastewater. In the electrolysis experiments with the simulated slurry, the optimal pH and current density were determined to be 8.5 and 22.2 A m −2 , respectively, achieving 95% phosphate removal efficiency and 100% current efficiency. The phosphate removal rate was mainly dependent on the magnesium dissolving rate. In the electrolysis experiments with the real digestion slurry, the pH of slurry increased from 7.4 to around 8.7 after the cathode-anode sub-section electrolysis without adding chemical reagents, achieving 93% phosphate removal efficiency at 22.2 A m −2 . The phosphate removal efficiency could be kept constant in three consecutive electrolysis cycles with both the anion exchange membrane and the cation exchange membrane. The cost of the magnesium anode treatment for the real biogas digestion slurry for struvite recovery was estimated to be $81.57 kg −1 P, mainly resulting from the consumption of electricity and magnesium anode. The precipitates collected from all experiments were identified as struvite by the X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Polycyclic complexes containing a bridgehead transition metal are interesting species because the transition metal is shared by all the rings simultaneously. In this study, we present a novel osmium-bridgehead system with three fused five-membered rings. This novel framework can be viewed as a 10-atom carbon chain coordinating to the osmium center. In sharp contrast to the nonplanar organic analogue, this unique metallacycle exhibits good planarity, which was unambiguously verified by means of X-ray diffraction. Interestingly, preliminary DFT calculations show that the aromaticity in the three 5MRs of these osmatricycles can be easily tuned by the ligand substitution. Finally, the broad UV/Vis absorption spectra of these novel polycyclic complexes were also reported. [ABSTRACT FROM AUTHOR]

Polycyclic complexes containing a bridgehead transition metal are interesting species because the transition metal is shared by all the rings simultaneously. In this study, we present a novel osmium-bridgehead system with three fused five-membered rings. This novel framework can be viewed as a 10-atom carbon chain coordinating to the osmium center. In sharp contrast to the nonplanar organic analogue, this unique metallacycle exhibits good planarity, which was unambiguously verified by means of X-ray diffraction. Interestingly, preliminary DFT calculations show that the aromaticity in the three 5MRs of these osmatricycles can be easily tuned by the ligand substitution. Finally, the broad UV/Vis absorption spectra of these novel polycyclic complexes were also reported. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2 ) thin films are deposited onto silicon (Si) substrates using magnetron sputtering technique. Raman spectra show that the out-of-plane vibration is preferentially excited for the film. X-ray diffraction patterns further illustrate that the deposited MoS 2 films have the preferential [100] orientation. These results demonstrate that the unit layers of S Mo S in the film are perpendicular to the substrate. This can supply high-speed paths for the transportation of the electron carriers along the out-of-plane orientation. Due to the unique vertically standing layered structure of the MoS 2 film, the fabricated MoS 2 /Si sensor device exhibits excellent hydrogen (H 2 ) sensing properties. The device performance can be featured by a high sensitivity (687.3% under 100.0 ppm H 2 ), high detection resolution (a 1.0-ppm level), as well as fast response and recovery, and good reversibility. The sensing mechanisms were discussed based on the microstructural characteristics of the MoS 2 film and the energy-band alignment near the MoS 2 /Si interface. The MoS 2 /Si heterojunctions proposed in this work might open new avenues for the development of future high-performance sensor devices. [ABSTRACT FROM AUTHOR]

Micro-mesoporous sieves MCM-41 with different pore diameters were synthesized under microwave irradiation, characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, N adsorption-desorption and temperature-programmed desorption of NH (NH-TPD). Intramolecular cyclization of N-Phenylanthranilic acid to acridone catalyzed by MCM-41 with different pore diameters was investigated. The results indicate that the yields increased significantly with the decrease of pore diameter of MCM-41. Furthermore, the yield of acridone under microwave irradiation was higher than that under conventional heating. [ABSTRACT FROM AUTHOR]

A di-vanadium-substituted Lindqvist-type polyoxometalate [Cu(C12H8N2)2]2[V2W4O19]·4H2O (1) was hydrothermally synthesized and characterized structurally by single crystal X-ray diffraction analysis. X-ray photoelectron spectroscopy and energy disperse spectroscopy tests further prove the existence of vanadium. Ultraviolet photoelectron spectroscopy and density functional theoretical studies indicate that the energy level of 1 matches well with the conduction band of the TiO2. Furthermore, considering the semiconductor-like nature of 1 and the introduction of transition metal element Cu synchronously extends the absorption to the visible region, which should also be beneficial to the photovoltaic device performance. 1-Doped TiO2 composites (denoted as 1@TiO2) have been successfully fabricated by a simple sol–gel method, and introduced into the dye-sensitized solar cells (DSSCs) as co-sensitizers in N719-sensitized photoanodes by mixing 1@TiO2 with P25 nanoparticles with different weight ratios to enhance the photoelectric conversion efficiency. The investigations show that the DSSC assembled with 1@TiO2/19P25 photoanode has the best performance and the overall improvement of the efficiency is 21.6% compared with pure P25. Furthermore, the electrochemical impedance spectroscopy and open-circuit voltage decay investigations show that the cosensitization of 1 and N719 can promote electron transfer and restrain charge recombinations in the DSSCs, resulting in a longer electron lifetime. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2 ) thin films were deposited on (1 0 0) Si substrates using magnetron sputtering technique and MoS 2 /Si heterojunctions were fabricated. X-ray diffraction patterns revealed that (0 0 1) crystal orientation is preferable in the films. Atomic force microscopy illustrated that the surface of the film is composed of dense nano-level grains. The current–voltage characteristics of the heterojunctions were investigated. The results showed that the heterojunctions exhibited obvious sensing properties to hydrogen gas (H 2 ) at room temperature (RT) when reverse voltages were applied on the heterojunctions. The sensing performance was featured by a high sensitivity, fast response and recovery, as well as good reversibility, and stable steady states. The sensing mechanisms were discussed in terms of the energy-band structure of the MoS 2 /Si heterojunction. [ABSTRACT FROM AUTHOR]

Copper gallium disulfide (CuGaS 2 , CGS) thin films were successfully prepared by sulfurizing Cu–Ga (CG) precursors in sulfur atmosphere which have been obtained through magnetron sputtering. Structural, chemical composition and optical properties of CGS films were analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy and UV–vis spectrophotometer. The results indicated that the CuGaS 2 films with a single-phase structure had formed at 450 °C and the crystallinity of this phase was improved with the increase in temperature. The composition of the films contains mainly CuGaS 2 chalcopyrite phase ( I 2 d ). And the crystal lattice parameters were a =b=5.3544 Å and c =10.4707 Å at a sulfurization temperature of 600 °C. The UV–vis spectroscopy indicated that the values of band gaps varied in the range of 2.31–2.46 eV within the temperature increasing from 450 to 600 °C. [ABSTRACT FROM AUTHOR]

CuInS 2 thin films were prepared by sulfurization of Cu–In precursor films through magnetron sputtering. The obtained films were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), UV–vis spectrophotometer and Hall Effect measurement. The results showed that the precursors films obtained at a sputtering power of 15 W were more dense and smooth. The CuInS 2 thin films sulfurized at 450 °C for 20 min demonstrated a typical chalcopyrite structure, with preferred orientation along the (112) plane and possessing 1.48 eV direct band gap. The study also illustrated that the composition of thin films almost kept stable while the film formation conditions changed, like sulfurization temperature and time, etc. The value of the direct band gap would increase with sulfurization temperature heating up. [ABSTRACT FROM AUTHOR]

A new methodology taking advantage of gold(I)-catalyzed ring expansion has been developed to assemble tricyclic 1 H-azocino[5,4- b]indoles from 2-propargyl-β-tetrahydrocarbolines. The azocinoindoles were obtained in moderate to excellent yields; the structure of which was established by X-ray crystallographic analysis. A mechanism involving regioselective intramolecular hydroarylation, [1,2]-alkenyl migration and carbon-carbon bond-fragmentation was proposed. [ABSTRACT FROM AUTHOR]

A new crown inorganic-organic hybrid material composed of the Keggin polyoxometalates and transition metal-amino acid coordination complexes, K{[KCu(gly)(OH)(HO)Cl][PWO]}·19HO ( 1), was synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis and single crystal X-ray diffraction. Compound 1 possesses of a 1D chain structure with a crown-type monomer, which is built up from [PWO] building blocks and tetranuclear [KCu(gly)(OH)(HO)Cl] rings. The [KCu(gly)(OH)(HO)Cl] ring consists of four Cu ions and four gly ligands, which exhibits the crown ether feature binding a potassium ion in its center. Further, two [KCu(gly)(OH)(HO)Cl] rings linked two Keggin polyoxoanions [PWO] into crown inorganic-organic hybrid material. Magnetic study shows the existence of ferromagnetic interactions in compound 1. [ABSTRACT FROM AUTHOR]

Abstract: Three-dimensional (3D) porous V2O5 and Fe0.1V2O5.15 thin films have been prepared by electrostatic spray deposition technique. X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy are employed to investigate the structures and valence states of the films. Galvanostatic cell cycling, cyclic voltammetry and impedance spectroscopy are used to characterize their electrochemical properties. The Fe0.1V2O5.15 thin film shows much better cycling performance than the non-doped V2O5 thin film. Fe3+ can act as a stabilizing agent in the layered V2O5 and increase the reversibility of the charge and discharge processes towards deeper depth of lithium insertion/extraction. The dissolution of the active material in the electrolyte can also be significantly suppressed in the Fe-doped sample. Nevertheless, the Fe-doping causes a slight decrease in lithium ion diffusion coefficient. [Copyright &y& Elsevier]

Abstract: The presence of coordinatively unsaturated metal centers in metal-organic frameworks (MOFs) provides an accessible way to selectively functionalize MOFs through coordination bonds. In this work, we describe thiol-functionalization of MOFs by choosing a well known three-dimensional (3D) Cu-based MOF, i.e. [Cu3(BTC)2(H2O)3] n (HKUST-1, BTC=benzene-1,3,5-tricarboxylate), by a facile coordination-based postsynthetic strategy, and demonstrate their application for removal of heavy metal ion from water. A series of [Cu3(BTC)2] n samples stoichiometrically decorated with thiol groups has been prepared through coordination bonding of coordinatively unsaturated metal centers in HKUST-1 with –SH group in dithioglycol. The obtained thiol-functionalized samples were characterized by powder X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscopy, infrared spectroscopy, and N2 sorption–desorption isothermal. Significantly, the thiol-functionalized [Cu3(BTC)2] n exhibited remarkably high adsorption affinity (K d =4.73×105 mLg−1) and high adsorption capacity (714.29mgg−1) for Hg2+ adsorption from water, while the unfunctionalized HKUST-1 showed no adsorption of Hg2+ under the same condition. [Copyright &y& Elsevier]

Abstract: A novel mediator-free biosensor was constructed by the co-intercalation of negatively charged DNA and positively charged hemoglobin (Hb) in the interlayer galleries of layered α-zirconium phosphate (α-ZrP) with the delamination-assembly procedure at pH 5.5. X-ray diffraction and field-emission scanning electron microscopy results revealed the featured layered structure for the re-assembled DNA/Hb/α-ZrP composite. Infrared spectroscopy and circular dichroism results confirmed the coexistence of Hb and DNA in the composite and the considerably retained protein conformation of intercalated Hb. The direct electron transfer of Hb was facilitated by the co-intercalation of DNA and Hb. Because of the synergistic effect of α-ZrP host and co-intercalated DNA guest, the DNA/Hb/α-ZrP modified electrode exhibited good electrocatalytic response to H2O2 with higher sensitivity of 0.79AM−1 cm−2 and lower detection of 4.28×10−7 M in the linear range of 7.28×10−7 to 9.71×10−5 M. Furthermore, the electrocatalytic activity of Hb in the DNA/Hb/α-ZrP composite retained at high temperature (85°C) or in the presence of organic solvent (CH3CN), which could be the protection of α-ZrP nanosheets. [Copyright &y& Elsevier]

Abstract: Four unknown compounds have been synthesized based on the molecular motif of 1-phenethyl-4-hydroxy piperidinium hydrochloride with a variety of the substituted groups R on the same carbon atom bearing the hydroxy group, such as 3-fluorophenyl (3a), 4-methoxyphenyl (3b), 4-methylphenyl (3c) and cyclohexanyl (3d), and their molecular structures were characterized by 1H NMR, MS and IR. To account for the stereo structure and provide more information on the effect of counter ions, hydrogen bonds on molecular conformation, the structure of [1-phenethyl-4-hydroxy-4-(3-fluorophenyl) piperidinium hydrochloride] [PHFPH.Cl] 3a was determined by the single-crystal X-ray analysis and optimized by the B3LYP/6-31G (d, p) calculations. Two chloride anions, two PHFPH cations and a dichloromethane molecule formed a five-membered structure ([(PHFPH)2Cl2]·CH2Cl2) via the intermolecular hydrogen bonds. The core of the five-membered structure ([(PHFPH)2Cl2]·CH2Cl2) is formed by two PHFPH cations linked by N(1B)–H(2)⋯Cl(2) hydrogen bonds of lengths 3.033(4), which is engaged in two hydrogen bonds: N(1A)–H(1)⋯Cl(1) of 3.110(4)Å and O(1B)–H(2B)⋯Cl(1) of 3.099(4)Å. The anti-tumor activity tests indicated that these compounds could inhibit the growth of the K562 cells to some extent and have the potential bioactivity of anti-leukemia. [Copyright &y& Elsevier]

Abstract: We have studied: (i) the sorption of arsenate on Mg–Al layered double hydroxides (LDHs) containing chloride (LDH-Cl) or carbonate (LDH-CO3) in the absence or presence of phosphate; (ii) the competitive sorption of arsenate and phosphate as affected by reaction time and pH and; (iii) the desorption of arsenate previously sorbed on the LDH by phosphate. The LDH samples were uncalcined (LDH-Cl-20 and LDH-CO3-20) or calcined at 450 °C (LDH-Cl-450 and LDH-CO3-450). More phosphate than arsenate was sorbed onto all the minerals but LDH-Cl-450 sorbed much lower amounts of both the ligands than LDH-Cl-20; vice versa LDH-CO3-450 showed a capacity to sorb arsenate and phosphate much greater than LDH-CO3-20. XRD analysis showed that arsenate was included into the layer spaces of LDH-Cl-20, but not in those of LDH-CO3-20. Competition in sorption between arsenate and phosphate was affected by pH, reaction time, surface coverage and sequence of addition of the ligands. Phosphate showed a greater affinity for LDHs than arsenate. The final arsenate sorbed/phosphate sorbed molar ratio increased with reaction time or by adding arsenate before phosphate, but decreased by increasing pH and by adding phosphate before arsenate. The effect of reaction time on the desorption of arsenate by phosphate was also studied. [Copyright &y& Elsevier]

Abstract: Holmium-doped lanthanum aluminate (LaAlO3) powder phosphors have been prepared at furnace temperatures as low as 500°C by using the combustion route without further calcining treatment. Powder X-ray diffraction and Fourier-transform infrared spectrometry measurements were used to characterize the prepared combustion products, while the optical properties were studied using UV–vis–NIR and photoluminescence spectroscopy. The Judd–Ofelt (J-O) model was applied to obtain the oscillator strengths (f) and three phenomenological intensity parameters. Using J-O parameters (Ω 2, Ω 4 and Ω 6) the radiative transition probabilities (A ab), radiative lifetimes (τ R) and branching ratios have been calculated for certain excited states of Ho3+. Using the Fuchtbauer–Ladenberg formula, the stimulated emission cross-sections (σ emi) for some interesting transitions, such as 5S2→5I8 and 5F5→5I8 of Ho3+ in LaAlO3, were determined and discussed. [Copyright &y& Elsevier]

Abstract: Selected samples of ternary Al–Mg–Sr alloys were investigated using thermal analysis, scanning electron microscopy and electron microprobe analysis. Additional samples, prepared in Montreal, were re-evaluated by simulation of their X-ray diffraction spectra and by careful analysis of their thermal analysis signal curves. A comprehensive and consistent thermodynamic description for the ternary Al–Mg–Sr system is generated by assessing all experimental data from the literature combined with the present experimental results. Extended ternary solid solubilities of binary phases and one ternary intermetallic phase are established in this system. Calculated phase diagram sections and the liquidus surface together with thermodynamic equilibrium and non-equilibrium Scheil calculations of selected alloys are used to demonstrate the good agreement with all of the experimental microstructures. This provides additional support for the thermodynamic description generated in this work. [Copyright &y& Elsevier]

A sonochemical method was applied to the preparation of monodispersed nanocrystalline PbSe in the presence of polyethylene glycol solvent. The nanocrytals were analyzed by X-ray diffraction (XRD), FT-IR, X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). It was found that the polyethylene glycol (PEG) as both a reducing agent and dispersant played an important role in the formation of monodispersed PbSe nanocrystals. [Copyright &y& Elsevier]